Method for Manufacturing a Component

ABSTRACT

A method for manufacturing a component from a hardenable aluminum alloy includes the steps of: heating a blank to a predefined temperature; shaping the heated blank into a semifinished product in a shaping tool; cooling the semifinished product during or following the shaping process; and shaping the cooled semifinished product into a component in a second shaping tool.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of PCT International Application No.PCT/EP2017/060007, filed Apr. 27, 2017, which claims priority under 35U.S.C. § 119 from German Patent Application No. 10 2016 208 014.8, filedMay 10, 2016, the entire disclosures of which are herein expresslyincorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a method for manufacturing a componentfrom a hardenable aluminum alloy.

Four fundamentally different methods have been established for formingaluminum. In the case of cold forming in the so-called T4 state, formingan aluminum plate is performed in a soft state. The component isthereafter hardened by artificial aging. In the case of W temper formingand forming in the W state, an aluminum plate is initially solutionannealed, subsequently quenched, and immediately formed in the very softstate. Artificial aging for hardening the material can also follow this.In the case of so-called warm forming, a hardened material is heated toapproximately 200 to 250° C. and is formed in this warm and softenedstate. Moreover, hot forming in which a hardenable alloy is heated totemperatures beyond 400° C. and is formed in a cold or hot forming toolis also known. In the forming of the hot aluminum sheet in the coldtool, a very soft state of the formed sheet results, similar to that ofthe state in W temper forming.

The W temper forming method sets higher requirements in terms of theprocess management of the systems technology, since the components haveto be formed in a tight temporal process window after the heattreatment. The degrees of deformation that are achievable arecomparatively small when compared to hot forming.

A method for manufacturing an aluminum formed part is known from DE 102008 032 911 A1. This method includes the following steps: placing analuminum sheet in a forming tool; partially forming the aluminum sheetto a partially formed aluminum sheet at room temperature; artificiallyaging the partially formed aluminum sheet; and subsequently finallyforming the partially formed aluminum sheet into a final shape of thealuminum formed part at room temperature.

A further method for manufacturing an aluminum formed part is known fromDE 10 2012 007 213. According to a first embodiment, an aluminum platethat is to be formed is heated and formed in a cooled forming tool whilebeing simultaneously quenched. According to a second embodiment, thealuminum plate after heating is quenched, provided with a lubricant, andformed in the cold state in a forming tool.

Proceeding from this prior art, the present invention is based on theobject of specifying a method for manufacturing a component by way ofwhich the disadvantages of the prior art are overcome. It is aparticular object of the invention to state a method by way of which thehighest possible degrees of deformation can be achieved. It is moreoveran object of the invention to specify a method which is distinguished byhigh cycle rates, or by a high simplification in terms of methodtechnology, respectively.

These and other objects are achieved by a method for manufacturing acomponent from a hardenable aluminum alloy, the method comprising thesteps of: heating a blank to a predetermined temperature; forming theheated blank to a semi-finished product in a forming tool; cooling thesemi-finished product, wherein cooling is performed after forming orduring forming; and forming the cooled semi-finished product to acomponent in a second forming tool.

In order for the object to be achieved, the invention proposes a methodfor manufacturing a component from a hardenable aluminum alloy.Hardenable aluminum alloys in the context of the invention are so-called7000 alloys or 6000 alloys as well as all further alloys which canachieve high strength values by hardening. In a first step of the methoda blank is heated to a predetermined temperature. Blanks are to beunderstood, for example, as aluminum plates which have previously beensevered from an aluminum coil. Of course, blanks can also be plateshaving a predetermined shape which are adapted to the final shape of thefinished component to be obtained. The blank is heated to apredetermined temperature in the range from 450 to 550° C., inparticular 500° C. According to a first embodiment, the heated blank isformed in a cold tool, wherein the blank when formed to thesemi-finished product is simultaneously cooled. According to a secondembodiment of the invention, the heated blank is initially cooled andthen formed in the forming tool. In both embodiments described, coolingor quenching, respectively, is performed to the ambient temperature. Theambient temperature here is in a range from 5 to 50° C. Thesemi-finished product after forming is present in a so-called W state.The blank in this state has a soft material structure.

The core concept of the invention is that in this state immediateforming in the cold state can follow without the component having to besolution annealed. By forming the cooled semi-finished product in asecond forming tool, almost the final shape of the component isgenerated. A semi-finished product in the context of the invention is aformed part that is shaped in two or three dimensions. A component inthe context of the invention is a formed part which is likewise curvedin two or three dimensions, the geometric shape and contour of saidformed part corresponding substantially to the finished component. Inother words, after the second forming only minor machining (or nomachining at all) is required in order to obtain the final shape of thecomponent. However, of course, bores can still be incorporated, coatingsapplied, or minor trimming performed on the component by post-machining.

Moreover, the heated blank can be formed to the semi-finished product ina preliminary forming step, and the cooled and pre-formed semi-finishedproduct can be finally formed to a component in a second forming stepthat, in terms of the contour, is close to the final contour. Very highdegrees of deformation can be realized when pre-forming in the heatedstate, without solidifications arising in the material. Only minoradaptations in terms of shape, in which the risk of solidifications inthe material of the component is comparatively minor, are implemented inthe case of the second forming that in terms of the contour is close tothe final contour. By combining hot forming in a first forming stage,wherein the warm material is formed in a cold tool, and, directlyfollowing this, forming in the W state as a second forming stage, thematerial of the aluminum sheet leaves the first forming stage in the Wstate, the latter in technical terms being able to be utilized for thesecond forming stage. This offers the advantage that an additional heattreatment which is otherwise required for the forming method in the Wstate, is eliminated. The forming capability of the material can thus beutilized in an optimal manner, and the manufacturing method can beshortened by one heating step. The so-called W state is defined inEN-515:2000 as the state directly after the annealing solution andquenching, and represents an unstable state, since the elongation atbreak/formability decreases on account of the storage at roomtemperature.

Furthermore, the cooled blank prior to forming in the second formingtool can be in a W state.

Furthermore, the component in a following method step can be hardened bya heat treatment. A heat treatment of this type can be performed in theform of artificial aging, for example. The component herein is heated toa temperature in the range from 80 to 250° C., preferably however to200° C. and is kept at this temperature for two hours. On accountthereof, the component is transformed to a so-called T6 state or aso-called T7 state. The states T6 and T7 are likewise defined inEN-515:2000.

Trimming of the pre-formed component or of the blank is preferablyperformed prior to the hardening of the formed semi-finished component.The blank, or the pre-formed semi-finished product, herein can betrimmed to a contour that is close to the final contour. This offers theadvantage that the trimming is performed in a comparatively soft state.As opposed to trimming of the finished, that is to say the hardened,component there is the advantage that the wear on the trimming tools canbe substantially reduced.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of one ormore preferred embodiments when considered in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In a schematic, simplified illustration herein:

FIG. 1 shows the method step of heating.

FIG. 2 shows the method step of first forming.

FIG. 3 shows the pre-formed semi-finished product.

FIG. 4 shows the method step of second forming.

FIG. 5 shows the method step of component hardening.

DETAILED DESCRIPTION OF THE DRAWINGS

As can be seen from FIG. 1, a pre-formed plate 10, with the aid of aheating installation 40, is heated to a predetermined temperature in therange of approx. 500° C.+/−10%. The heated blank 10 is incorporated intoa first forming tool 20 which comprises an upper tool half 21 and alower tool half 22. The two tool halves 21, 22 for closing are capableof being converged, and for opening are capable of being diverged. Theheated blank 10 is formed to a semi-finished product 11 by closing thetwo tool halves 21, 22. High degrees of deformation are achieved hereinsuch that the main forming work which is required for forming the blank10 to the finished component 12 is already performed in the firstforming step in the tool 20. The formed semi-finished product 11 hereincan be quenched simultaneously with the forming in the forming tool 20.

Alternatively thereto, said formed semi-finished product 11 can besubsequently actively or passively cooled to room temperature, or to theambient temperature, respectively, for example by air, as is illustratedin FIG. 3.

As soon as the formed semi-finished product 11 has been cooled, thelatter is incorporated into a second forming tool 30. The latter, in amanner analogous to that of the first tool 20, likewise comprises anupper tool half 31 and a lower tool half 32 which are capable of beingconverged and diverged. The pre-formed semi-finished product 11 isshaped to the final contour of the finished component 12 by closing thetool halves 31 and 32. As can be seen from FIG. 4, only minor degrees ofdeformation are achieved herein. The component 12 formed to the finalcontour, or the component 12 that is formed only so as to be close tothe final contour, respectively, is retrieved from the second formingtool 30 and is hardened with the aid of a heat treatment. This heattreatment, in which the component 12 with the aid of a second heatinginstallation 50 is heated to a predetermined temperature, for example inthe range from 180° C. to 250° C., is shown in FIG. 5. The finishedcomponent has predetermined strength properties once the component hasbeen exposed to this temperature for a predetermined time, for example 2hours.

On account of the above, an aluminum component, or an aluminum formedpart which is hardened to the state T6 or T7, respectively, and is twiceformed is created as a final product of the method. Higher degrees ofdeformation are achieved by the method, and components of which thegeometry could not be reproduced by a single method step are produced onaccount of said method. Moreover, a cost optimization is performed bydispensing with a heat treatment stage which can be saved by virtue ofthe combination of processes.

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

What is claimed is:
 1. A method for manufacturing a component from ahardenable aluminum alloy, the method comprising the steps of: heating ablank to a predetermined temperature; forming the heated blank to asemi-finished product in a forming tool; cooling the semi-finishedproduct, wherein cooling is performed after forming or during forming;and forming the cooled semi-finished product to a component in a secondforming tool.
 2. The method as claimed in claim 1, wherein the heatedblank in a preliminary forming step is pre-formed to the semi-finishedproduct; and the cooled and pre-formed semi-finished product is finallyformed to a component in a final forming step.
 3. The method as claimedin claim 1, wherein the cooled semi-finished product prior to forming inthe second forming tool is in a W state.
 4. The method as claimed inclaim 1, wherein the component is hardened by a heat treatment.
 5. Themethod as claimed in claim 1, wherein trimming of the component, of thesemi-finished product or of the blank is performed prior to hardening ofthe component.